Down's syndrome (DS) is one of the most common genetic abnormalities in humans and most often results from full or partial trisomy of chromosome 21. It is a complex clinical syndrome associated with higher risk of multiple pathological conditions, including heart problems, motor skills and cognitive deficits, a reduced incidence of solid tumors, and both early onset and higher incidence of aging-related phenomena such as Alzheimer's disease (Antonarakis, S. E., et al. Chromosome 21 and Down's syndrome: from genomics to pathophysiology. Nat. Rev. Genet. 5, 725-738 (2004); Yang, Q., et al. Mortality associated with Down's syndrome in the USA from 1983 to 1997: a population-based study. Lancet 359, 1019-1025 (2002); Satgé, D. et al. A tumor profile in Down's syndrome. Am. J. Med. Genet. 78, 207-216 (1998); Roth, G. et al. Premature aging in persons with Down's syndrome: MR findings. AJNR Am J Neuroradiol 17, 1283-1289 (1996); Carmeliet, G., et al. Cellular ageing of Alzheimer's disease and Down's syndrome cells in culture. Mutat. Res. 256, 221-231 (1991); Zigman, W. B. et al. Alzheimer's disease in Down's syndrome: neurobiology and risk. Ment Retard Dev Disabil Res Rev 13, 237-246 (2007)).
Down's syndrome is but one of many medical conditions that are associated with a reduction in the rate of tissue-specific stem cell self-renewal, and/or that will be treated by increasing the rate of tissue-specific stem cell self-renewal. What is need are better methods and therapeutics for alleviating the symptoms of these conditions. The present disclosure addresses these issues.